Definitions

Circular Motion
Circular Motion-The movement of an object at a constant speed around a circle with fixed radius.
Axis-Straight line around which rotation takes place.
Rotation- Object turns around in an internal axis.
Revolution- Object turns around an external axis.
Linear Speed- Distance time.
Tangential Speed- Speed along a circular path.
Rotational Speed-Number of rotations per unit of time.
Centripetal Force- Force that causes an object to follow a circular path.

Gravity and Weight
Gravity- A constant force exerted by objects that have a mass.
Weight- The pull of gravity.
Newton- The unit of force in which is measured by weight.
Law of gravitation-Every object in the universe attracts every other object.
Gravitational Attraction- The force of attraction between objects.
Law of universal gravitation- States that gravitation forces were responsible for the acceleration of objects on the moon and on the earth.

Friction
Static friction force-Exerted on one surface by the other when there is no relative motion between two surfaces.
Kinetic friction force- Is the force exerted on one surface by the other when the surfaces are in relative motion.

Coulomb's Law/Electric Fields
Coulomb's Law- The relationship among electrical forces, charges, and distance.
Electric Fields- A vector quantity that relates the force exerted on a charge to the size of the charge.
Electric Potential Difference- Causes charges to move.
Grounding- Touching a body to earth to eliminate excess charge.
Electric Current- Flow of charged particles.

Explanation

The formula that explains Centripetal force is as follows:
external image cf.gif

To convert pounds to newtons you must multiply the number of pounds by 4.45, since 1 pound equals 4.45 newtons.

The formula that explains Newton'a Law of gravity is as follows:
external image GravityEq1.jpg